Manhole and cover



Jan. 3, 1933. O DOUGHERTY 1,892,830

MANHOLE AND COVER Filed Dec. 50 1930 l/im /flar OWE/Y 770006 155 7'):

Patented Jan. 3, 1933 PATENT OFFICE OWEN '1. DOUGHER'IY, OF ST. PAUL, MINNESOTA MANHOLE AND COVER Application filed December 30, 1930. Serial No. 505,633.

This invention relates more particularly to manholes for sewer and other underground mains and is an improved construction of the manhole disclosed in Patent No. 1,177,- 850, granted to me April 4, 1916.

The object of the invention is to provide a manhole and cover of this class in which the cover, when in place in the outer manhole housing, will interlock with the housing to prevent its rattling when passed over by vehicles, and which at the same time will afford an improved uniform support for the cover with less accuracy, lighter weight, and cheaper manufacture of both the housing and the cover. A further object is to provide improved facilities for the easy unlocking and ready removal of the cover from the housing.

The invention consists in the constructions and combinations hereinafter described in the specification and particularly pointed out in the claims.

In the accompanying drawing illustrating the invention and forming a part of the specification,

Figure 1 is a plan view of a manhole housing and cover with half the cover broken away tomore plainly show its supports.

Figure 2 is a vertical section on the line 22 of Fig. 1.

Figures 3 and 4 are similar sections on the lines 33 and 4-4 respectively of Fig. 1.

In the drawing the numeral 6 represents the housing usually of cylindrical form and supported by the annular flange 8. Integral with the cylindrical wall of the housing are cast a series of inwardly projecting main supporting lugs 10, having an upper supporting surface 12 and an interlocking under surface 14. A series of inwardly projecting auxiliary lugs 16 are spaced from the lugs 10 and are preferably provided with an upper inclined surface 18. a beveled surface 20 and a wedge face 22. Spaces 24 are arranged between the wedge faces 22 and the lower ends of the main supporting lugs 10 and spaces 26 separate the auxilliary lugs 16 from the upper interlocking ends of the lugs 10, the purpose of which will hereinafter appear.

The cover 28 having the usually checkered or roughed upper surface 30 is provided with a series of integral downwardly projecting circumferentially spaced seat lugs 32, correspending in number and position to the main supporting lugs 10 of the housing 6. The under side of the seat lugs 32 are inclined at an angle corresponding to theupper inclined surface 12 of thesupporting lugs 10. Slightly tapering locking lugs 34 cast integral with the cover 28, project downward at an angle to the horizontal plane and tangent to the circular edge of the cover. The upper inclined face 36 of the lugs 34 is adapted to interlock with the inclined face 14 of the supporting lugs 12 and the lower inclined face of the auxiliary lugs 16. The locking lugs 34 are preferably integral at their upper ends with the seating lugs 32 while between their lower projecting ends and the opposite upr per ends of the lugs 32 is arranged a clearance space 40. Recesses 42 and 44 are provided in the circular edge and on opposite sides of the cover in positions over two of the spaces 24 between the wedge faces 22 and the lower ends of the supporting lugs 10, when the 1 cover is in place as shown in Figs. 2 and 3. The recesses 42 and 44 in the cover 28 are arranged between the seating lugs 32 and interlocking lugs 34. lVhen the cover is in place. the inclined under sides of the seating lugs 32 bear solidly on the upper inclined surface 12 of the supporting lugs 10. while the locking lugs 34 engage the interlocking under surface 14 of the succeeding supporting lug 10. The cover is thus firmly locked in place and can onlv be unlocked and removed by a turn to the left as indicated by the arrow in Fig. 3; It will be noted that in the locked position the deep end of the resting lugs 32 projects overthe lowest end of the supporting lugs 10 a distance not less than the locking lugs 34 project under the interlocking ends of the supporting lugs 10.

\Vhen the cover i s to be removed a chisel or wedge 46 indicated in dotted lines in Fig. 3, is inserted in one or both of the recesses 42 and 44. engaging on one side the wedge faces 22 of the auxiliary lugs 16 and on the other s1de the deeper end of the seating lugs 32 on the opposite side. The driving down of the 38 has the same incline as the upper face 18 Wedge will force the cover to rotate upon its inclined seats and at the same time raise up above the upper edge of the manhole housing, unlocked and in a position to be removed. The incline of the supporting lugs exceeds the angle of repose sufficiently so that when the cover is again replaced it automatically turns into a lock-ed position bearing uniformly on all supporting lugs proof against rattlng and since the supporting lugs are of an even number, and like construction the two unlocking recesses in the cover will always align with two wedge spaces on replacementof the cover.

I claim as my invention:

1. A manhole comprising an outer housing having a series of inwardly projecting spaced apart cover seating members, the said members each having an upper seat surface inclined to the horizontal plane, said members having each an inclined interlocking under surface, and a series of lugs arranged near the top of the housing and having upper inclined surfaces, a cover adapted to be interlocked with the housing against vertical movement of the cover, the said cover having lugs constructed to bear against the upper inclined surfaces of said members and lugs and against said interlocking under surfaces of said members when the cover is rotated into closing position.

2. A manhole cover having a series of circumferentially arranged seat members, the said members having each two spaced seating faces inclined to the horizontal plane and tangentially projecting locking lugs having an upper interlocking surface of a greater inclination to the horizontal plane than the seating faces of the said seat members.

3. A manhole comprising an outer housing having a series of inwardly projecting cover seat members, the said members having each an upper seat surface and an inclined under surface, inclined to the horizontal plane, a second series of lugs adapted to be interlocked with the cover of the housing, and cover seat members spaced apart, said seat members of the cover having inclined surfaces constructed to bear against the said upper and under surfaces of the said housing members and lugs, when the cover is rotated into closing position.

4. In a manhole and cover the combination with a housing having a series of spaced apart inwardly projecting seat members, the said members having an upper seat surface inclined to the horizontal plane, of a series of interlocking lugs projecting inwardly from said housing, a cover having a series of circumferentially arranged seating members adapted to seat upon the seat members of the housing and tangentially projecting lugs having an upper surface of greater inclination to the horizontal plane than the upper surface of the said seat members and adapted,

OWEN T. DOUGHERTY. 

